Connective Tissue Flashcards
What conditions are there abnormal amounts of collagen present in tissue?
Fibrosis Collagen tumors Benign fibromas Malignant fibro-sarcomas Collagen diseases --> Scleroderma
What are the main chemicals and each of their purpose in Masson’s Trichrome?
- Post Fixation in Bouin’s –> Increases Acidophilia (enhances red colour)
- Weigert’s Hematoxylin –> Nuclear stain
- Biebrich Scarlet – Acid Fuchsin –> Cytoplasmic stain
- Phosphotungstic and Phosphomolybdic Acid –> Differentiation
- Light Green or Aniline Blue –> Collagen stain
- Acetic Acid Water –> Removal of excess collagen dye
What type of hematoxylin in Weigert’s in Masson’s Trichrome and why is that type used?
Iron Hematoxylin.
- Used to progressively stain nuclei.
- Will hold colour in nuclei; if a Alum hematoxylin would decolorize in PTA/PMA (strong acid)
- Acts as a mordant and oxidizer (needs to be fresh).
Why are both Biebrich Scarlet and Acid Fuchsin both used as a cytoplasmic stain in Masson’s Trichrome?
Two different red acid dye solutions. Combined to stain cytoplasm and collagen temporarily. Biebrich Scarlet is the smaller dye molecule out of the two red dye solutions.
The red dye that goes to the collagen will get removed later by the Phosphotungstic and Phosphomolybdic acid solution.
What is Phosphotungstic and Phosphomolybdic Acid in Masson’s Trichrome and specifically what does it remove?
Phosphotungstic and Phosphomolybdic Acid –> PTA/PMA
Two different acid solutions that creates one strong acid solution to remove the acid fuchsin dye molecules from the collagen (like it was reserving space for another dye).
What dye in Masson’s trichrome dyes the collagen after the acid solution?
Light green or aniline blue stains the collagen in the tissue.
Colour chosen depends on the preference of the pathologist.
What happens if 1% acetic acid wash is not done in Masson’s Trichrome?
If the excess collagen stain on the tissue is not removed it can result in a muddy background appearance of the slide.
This occurs when the collagen stain, the biggest dye molecule, is all over tissue areas other than just collagen.
If you finish Masson’s Trichrome stain and find there is too much overall blue colour on the tissue what can you do?
Place slides in acetic acid for a longer time.
What happens if you don’t use Bouin’s in Masson’s Trichrome technique and why does RRC not use it then?
Without Bouin’s –> get pale staining collagen and pale red cytoplasm and muscle.
But Bouin’s has picric acid which if it dries out during storage becomes explosive.
What happens in Masson’s Trichrome if the Iron Hematoxylin is not made fresh?
Nuclei will stain pale or not at all.
What are the colours for Masson’s Trichrome?
Nuclei --> Black (but maybe dark grey or dark purple) Cytoplasm --> Red Muscle --> Red RBC --> Red Collagen --> Blue or green
What are the main chemicals involved in Gomori’s Aldehyde Fuchsin?
- Aldehyde Fuchsin –> stains progressively
- 70% Ethyl Alcohol –> removes excess colour from background
- Van Gieson’s Counterstain –> two dyes one stains collagen the other stains all other tissue components.
What does Gormori’s Aldehyde Fuchsin stain?
Stains elastic fibers and other components like mast cell granules, beta cell granules, gastric chief cells, and some mucins.
Note: This stain is not necessarily specific for elastic fibers and mast cells.
What staining technique is specific for mast cells?
Toluidine Blue
What does Aldehyde Fuchsin consist of in Gomori’s Aldehyde Fuchsin technique?
Aldehyde Fuchsin:
- Basic fuchsin,
- 70% alcohol, HCl, and
- Paraldehyde.
Stains Progressively